Technical Field
The present disclosure relates to an apparatus for growing a single crystal and a method for growing a silicon single crystal, and more particularly to an apparatus for growing a single crystal and a method for growing the same, which provide a thermal environment in which silicon melt accommodated in a crucible can be quickly melted inside the crucible.
Background Art
In general, silicon single crystals used as substrates for manufacturing semiconductor devices are manufactured by using the Czochralski (Cz) method. In the Cz method, silicon single crystals are introduced into a quartz crucible, and then the crucible is heated, so that a single crystal seed contacts silicon melt and is then grown to produce a single crystal while being slowly pulled upwards.
Most crystal manufacturing apparatuses are made of steel, have a circular shape, and include a heat insulation member for blocking heat therein, a heating element for melting silicon, a graphite crucible surrounding a quartz crucible, a support shaft supporting the crucible, and so forth. These inner structures are referred to as a “Hot zone”.
In order to grow a high quality silicon single crystal, a thermal environment around an interface is uniformly formed and maintained, so that the quality of the single crystal and the pulling speed should be maintained and the pulling speed should be readily controlled even though the single crystal grows to a greater length. More specifically, the silicon melt continuously receives heat from the heater, and the loss of heat is blocked by a heat shielding structure, so that a predetermined temperature gradient is maintained.
However, as the silicon ingot comes to have a larger diameter, the size standard for an apparatus for growing a single crystal becomes greater, and more particularly, when a crucible becomes larger, poly silicon to be melted in the crucible cannot be liquefied in a short time, so that the process time for growing a single crystal becomes longer. Also, when a solidification of silicon melt is locally generated because the silicon melt itself cannot be maintained at a uniform temperature, there are problems in that a loss is generated in a silicon single crystal which is to be grown, and the quality of the grown single crystal is also affected. Also, there is a problem in that a loss occurs in a silicon single crystal because a non-uniform temperature distribution occurs at the surface of the melt and inside the melt in a crystal growing process.